Lu and Cosmo are flying to the Norwegian capital Oslo when Lu reminds his friend of something: "Cosmo, did you know that the north of Norway is actually near the Arctic circle? That means that the sun doesn't set in summer and in winter it is dusk all day, so it never really gets light." Cosmo looks puzzled: "That means it'll be light the whole time because it is summer now?" "Exactly," Lu replies.
Once in Oslo, they begin their adventures in the Nobel Prize Museum. In the museum, children are sent on a mission to solve a case. "From now on you can call me Agent Cosmo!", Cosmo cries proudly, because he has solved his case and received an official agent ID.
"Unbelievable how many people have tried to secure peace in the world!", Lu marvels. "Now I know that since 1901 the Nobel Peace Prize has been awarded every year in Oslo and is named after its inventor, Alfred Nobel. You can be really proud of yourself if you receive one!", he explains to Cosmo.
The next morning Lu and Cosmo are out discovering Oslo by water. "The Oslo fjord dates back to the last ice age and is 120 kilometres long," Lu reads in his guidebook. They take the ferry from the city hall over to the Bygdoy museum island. There are four museums there where the two hear exciting stories of Norwegian expeditions and even see three authentic Viking ships.
Lu and Cosmo can hardly keep their eyes open in the evening after learning and discovering so much. Although it is still light outside, the two friends are soon sound asleep. "Good night, Lu," whispers Cosmo. "God natt. Good night, Cosmo," replies Lu and falls asleep right away.